Brians Bullet (oz3007)

About this Plan

Brian's Bullet. Free flight power trainer model for Cox Tee Dee .020 engine.

Direct submission to Outerzone.

Update 01/04/2020: Added article, thanks to RFJ.

Quote: "Here's an excellent advanced trainer for the budding competition free flighter. For smaller field competition, why not a new event for 1/4A? Brians Bullet, by Loren Williams.

Eight years ago this model was designed for my then, nine year old son Brian. Assured performance and simplicity were the design goals for his first gas model. The Bullet is strange looking; not a pylon, not a high thrust, and not a cabin job. No kits available look like this. And why the hodge podge of different construction? These things were done on purpose; to embody in a beginner's model the potential of learning as many construction techniques as possible and to enjoy flying a model that was different from the regular standards.

A total of four models have been built to date; my son's original, one by 15 year old Larry Li China, one by another flying buddy, Bill Reid, and the one presented in this article. All of the Bullets built fly consistently with a steep right power pattern and a right glide circle.

Don't let the special backing plate for your Cox TD .020 stop you. It is available from the author for $5.50. See plans for address.

CONSTRUCTION: Beginners, attention: All successfully concluded ventures start with sound planning and proven principles. Your first gas model is no different. FIRST: Study the plans and read the construction article, until you understand how each component is made and in what sequence it goes together.

Wouldn't it be great to open a kit box on your work bench and have all parts cut and shaped to their finished sizes ready to glue together? Well! Make a list of all materials and head for your local hobby shop. Make your selection critically, for straightness, light weight and proper hardness. Get a box and you are ready to pre-fab your own kit.

Although this article will be broken into basic assemblies, read each one carefully and pick out all the components that can be pre-fabricated. When your kit is finished you will find the actual construction time is very short, because there is always something to glue together, while something else is drying.

Ambroid fast drying cement was used for all balsa joints, except sheeting (see below). Formula 4 for epoxy joints.

FIREWALL AND SKID: Cut three 1/16 plywood laminations to shape down on plan. Form landing skid from .062 music wire to match sideview and fold over top end as shown in firewall detail. Remove area for skid in the center plywood lamination. Epoxy skid and all laminations together. When dry, drill two .093 dia. holes to match engine backing plate. Epoxy 2-56 nuts on rear of firewall. NOTE: Because of the left thrust the skid will be slightly askew, this can be straightened by hand forming after model is completed.

WING CONSTRUCTION: Most model shops may not carry this specific size TE stock. If not, cut 1/8 of trailing edge off of standard 3/16 x 3/4 TE stock and block sand to finished dimensions.

Cut 24 basic ribs oversize, pin together, block sand to final shape, trim for front sheeting and notch for spars. The center ribs must have an additional 1/32 removed from bottom and aft of top spar for sheeting. Also the four center, tip, and tip dihedral ribs are not notched into TE so 1/16 should be removed from rear of these ribs.

Shape leading edge to a sharp, pointed section as shown in center section view. Cut out all dihedral and triangular gussets.

Cover plan with Saran Wrap, cut TE stock to proper lengths, notch for ribs and pin to plan. Pin down LE and bottom spar, cut four pieces of 1/32 sheet for center section, cement to LE, TE, and spar, but not together. Now cement in all ribs except four center section and tip dihedral ribs.

When dry, remove wing panels from plan, bevel LE, TE, and bottom spar of each panel to mate with adjoining panel, using dihedral gusset as a guide. Pin down one main panel, block up ad- joining main panel to correct dihedral... "

Supplementary file notes

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